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39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
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#pragma once
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#include <array>
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#include <cstddef>
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#include <vector>
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template<class T>
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struct span
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{
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public:
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using element_type = T;
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using pointer = T*;
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using reference = T&;
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using iterator = T*;
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constexpr span() noexcept : m_ptr(nullptr), m_count(0) {}
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constexpr span(std::nullptr_t) noexcept : span() {}
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constexpr span(T* ptr, size_t count) noexcept : m_ptr(ptr), m_count(count) {}
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constexpr span(T* ptr_begin, T* ptr_end) noexcept : m_ptr(ptr_begin), m_count(ptr_end - ptr_begin) {}
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template<size_t N>
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constexpr span(T (&arr)[N]) noexcept : span(arr, N)
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{
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}
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span(std::vector<T>& v) noexcept : span(v.data(), v.size()) {}
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span(const std::vector<std::remove_const_t<T>>& v) noexcept : span(v.data(), v.size()) {}
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constexpr iterator begin() const { return m_ptr; }
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constexpr iterator end() const { return m_ptr + m_count; }
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constexpr reference operator[](size_t i) const { return m_ptr[i]; }
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constexpr size_t size() const { return m_count; }
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private:
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pointer m_ptr;
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size_t m_count;
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};
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